Continuously Variable Transmission

ABSTRACT

A continuously variable transmission comprises an input shaft and an output shaft, a drive wheel, a toothed wheel or a chain wheel, an endless sleeve, a ring wheel, at least one linking member, wedge teeth or a chain, wherein the drive wheel is provided with an annular recess in which a plurality of reversal wedge teeth run, and the wedge teeth are connected with a head portion of the linking member connected with the ring wheel, the spread of axles between the drive wheel and the ring wheel is adjusted via the swinging of the endless sleeve; and with the aid of the locking and releasing operations of the wedge teeth, the linking members are urged to drive the ring wheel, whereby changing the input and output transmission ratio. The continuously variable transmission can be used in a bicycle, wherein the spread of axles between the ring wheel and the drive wheel can be adjusted by regulating a wire, and the magnitude of speed variation is not restricted, the variation range is large, and the power could be synchronously input during the speed variation.

TECHNICAL FIELD

The present invention relates to a transmission, and more particularly,a continuously variable transmission capable of a continuous andconstant variation of a running speed thereof.

BACKGROUND OF THE INVENTION

In different kinds of motor vehicles, bicycles, machine equipments suchas machine tools or the like, a transmission is widely used for alteringinput and output transmission ratios to attain a desired acceleration ordeceleration.

A conventional transmission basically consists of different gears ofvarious sizes. For example, a manual or an automatic transmission for amotor vehicle may provide a 4- to 5-speed transmission, in which eachspeed section needs to shift in a stepped manner, namely to shift froman upper section to a lower section and then from the lower section to anext section, such an operation process would be quite complicated, andsometimes a momentary failure might occur during the shifting process.

As far as a simple transmission for a bicycle is concerned, thistransmission adopts usually a so-called conical pulley having aplurality of chain wheels of diameters varying in magnitudesequentially, the transferring of the chain among various chain wheelsis quite unsmooth, resulting in a relatively long time for speedvariation, and a failure might occasionally occur.

Among the commercially available continuously variable transmissions, acontinuously variable transmission of belt-type is desirable, which isformed by having a belt covering on two wheels which are capable ofchanging the diameter of a V-shaped slot. This type of transmission hasadvantages of being simple in structure and easy in speed variation; butboth ends of the belt are subject to a huge friction during operation,such that the belt is continuously bent and straightened to an extent,and thus prone to wearout and outbreak, even energy loss. Such abelt-type continuously variable transmission is not suitable for use inmotor vehicles having a large horsepower.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a continuously variabletransmission capable of a smooth and continuous variation of an inputand output transmission ratio thereof. The continuously variabletransmission has its operation completely different from theconventional transmissions which transmit power through friction. Thetransmission of the invention allows to minimize the friction during thetransmission of the power of its drive wheel.

To attain the above object, the present invention provides acontinuously variable transmission comprising:

a support consisting of two bearer plates and a base plate;

a drive wheel acting as a primary wheel in round shape, which has anannular recess arranged near its periphery and is rotatably mounted atan upper portion of the bearer plate by an input shaft;

a toothed wheel acting as a driven wheel, which is rotatably mounted ata lower portion of the bearer plate by an output shaft;

an endless sleeve having an annular groove arranged on its innercircumferential surface, and a projecting lug or driving element and amounting cannula protruding outwardly and located at corresponding upperand lower portions on its outer circumferential surface, respectively;

a ring wheel which is an annular external gear having on its outerperipheral surface a toothed portion with a relatively large diameterconvex intermediate section and a relatively recessed supporting stephaving its both laterals with a diameter smaller than a root circlediameter of its toothed portion, and a plurality of perforated mountingbulges being evenly distributed on its inner peripheral surface; whereinthe ring wheel is mounted in the endless sleeve and has its toothedportion inserted into the annular groove of the endless sleeve andmeshed with toothed portion of the toothed wheel at the lower portion ofthe support; while the supporting step is in slidable contact with topsurfaces of both lateral walls of the annular groove; and the ring wheelis concentrically arranged with the drive wheel and movable with respectto the drive wheel so as to attain an adjustable spread of axles with aspecific speed variation;

at least one linking member having the number corresponding to thenumber of the bulges of the ring wheel, each linking member comprising ahead portion and a linking portion, wherein the head portion has anintermediate cylindrical portion and two circular shafts located at itsboth ends; and the linking portion extends radially from theintermediate cylindrical portion of the head portion and has an apertureat its free end;

at least two wedge teeth having the number in relation to the number ofthe circular shafts of the linking member, two wedge teeth being mountedon each linking member; wherein each wedge tooth consists of first andsecond wedges of hinge type with circular-arc-shaped top surfaces and ismuff-coupled with one circular shaft of the head portion of the linkingmember; when the wedge teeth are mounted on the circular shafts, eachlinking member is rotatably mounted in the annular recess of the drivewheel via a bearing, the linking portion of each linking member has itsfree end articulated with the bulges of respective ring wheel via apintle, and the first and second wedges are expanded by a resilientmember, such that the circular-arc-shaped top surfaces and inner wallsof the annular recess of the drive wheel create a reverse frictionalcontact when the drive wheel rotates.

In the above continuously variable transmission, the drive wheelconsists of two flat wheels being mounted respectively at the inputshaft in a relatively spaced manner, the annular recess is relativelyarranged at an inner surface near periphery of the flat wheels, and thewedge teeth on the two circular shafts of the linking member arerespectively located in the annular recess of the two flat wheels.

The first and second wedges respectively have a hinge gaine and a wedgeteat axially arranged at an outer circumferential surface of the gaine,wherein the hinge gaine of the first wedge is located at the middle ofthe wedge teat, and the second wedge has two hinge gaines respectivelylocated at both sides of the wedge treat; and the hinge gaine at themiddle could be matchably inserted into the hinge gaines at both sides,such that they are located on a common axis, while their wedge teats areopposite to each other up and down.

The wedge teat has a lateral surface which is a flat surface, and a topsurface which is a circular-arc-shaped wedge surface constituted by twosmoothly transited circular arcs with different radii, wherein the arcshave a radius which is relatively large at the region near the lateralsurface and relatively small at the region far away from the lateralsurface, the lateral surface is further provided correspondingly with arabbet, and the resilient member is a spring bow having its two endsinserted into the rabbet, such that the first and second wedges areelastically pushed to the circular-arc-shaped wedge surfaces so as tocome into contact with a inner wall of the annular recess of the drivewheel.

To attain the above object, the present invention provides anothercontinuously variable transmission comprising:

an input shaft and an output shaft arranged in an axle seat of anexternal support;

a drive wheel acting as a primary wheel in round shape, which has itscenter hole as an axle hole for mounting the input shaft, and an annularrecess arranged near its periphery;

a chain wheel acting as a driven wheel, which has its center hole as anaxle hole for mounting the output shaft;

an endless sleeve consisting of an endless sleeve portion and a handleportion extending outwardly from one end of the endless sleeve portion,wherein the endless sleeve portion has an annular groove arranged on itsinner circumferential surface, and a projecting lug protruding outwardlyfrom an upper portion of its outer circumferential surface, and a forepart of the handle portion is provided with a mounting hole capable ofrotatably connection with the output shaft when the endless sleeveswings;

a ring wheel which is an annular chain wheel having on its outerperipheral surface a toothed portion with a relatively large diameterconvex intermediate section and a relatively recessed supporting stephaving its both laterals with a diameter smaller than a root circlediameter of its toothed portion, and a plurality of perforated bulgesbeing evenly distributed on its inner peripheral surface; wherein thering wheel is mounted in the endless sleeve portion of the endlesssleeve and has its toothed portion inserted into the annular groove ofthe endless sleeve portion of the endless sleeve; while the supportingstep is in rolling contact with top surfaces of both lateral walls ofthe annular groove; and the ring wheel is concentrically arranged withthe drive wheel and movable with respect to the drive wheel such thatits axle center and axle center of the drive wheel establish aneccentric spread of axles that is adjustable within a specific range;

at least one linking member having the number corresponding to thenumber of the bulges of the ring wheel, each linking member comprising ahead portion and a linking portion, wherein the head portion has anintermediate cylindrical portion and two circular shafts located at itsboth ends; and the linking portion extends radially from theintermediate cylindrical portion of the head portion and has an apertureat its free end;

at least two wedge teeth having the number in relation to the number ofthe circular shafts of the linking member, two wedge teeth being mountedon each linking member; wherein each wedge tooth consists of first andsecond wedges of hinge type with circular-arc-shaped top surfaces and ismuff-coupled with one circular shaft of the head portion of the linkingmember; when the wedge teeth are mounted on the circular shafts, eachlinking member is rotatably mounted in the annular recess of the drivewheel via a bearing, the linking portion of each linking member has itsfree end articulated with the bulges of respective ring wheel via apintle, and the first and second wedges are expanded by a resilientmember, such that the circular-arc-shaped top surfaces and inner wallsof the annular recess of the drive wheel create a reverse frictionalcontact when the drive wheel rotates;

a chain mounted on chain teeth of the ring wheel and the chain wheel inan enclosing manner for driving rotation of the output shaft.

To attain the above objection, the present invention provides a stillanother continuously variable transmission comprising:

a support consisting of two bearer plates and a base plate;

a drive wheel having an annular recess arranged near its periphery andbeing rotatably mounted at an upper portion of the bearer plate by adrive wheel shaft;

a toothed wheel acting as a driven wheel, which is rotatably mounted ata lower portion of the bearer plate by an output shaft;

an endless sleeve having an annular groove arranged on its innercircumferential surface, and a projecting lug and a mounting cannulaprotruding outwardly and located at corresponding upper and lowerportions on its outer circumferential surface, respectively;

a disk-type ring wheel which is an disk-shaped external gear having onits outer peripheral surface a toothed portion with a relatively largediameter convex intermediate section and a relatively recessedsupporting step having its both laterals with a diameter smaller than aroot circle diameter of its toothed portion, and a plurality ofisometric sliding chutes being radially and equangularly arranged on itsdisk surface; wherein the disk-type ring wheel is mounted in the endlesssleeve and has its toothed portion inserted into the annular groove ofthe endless sleeve and meshed with toothed portion of the toothed wheelat the lower portion of the support; while the supporting step is inslidable contact with top surfaces of both lateral walls of the annulargroove; and the disk-type ring wheel is concentrically arranged with thedrive wheel and movable with respect to the drive wheel so as to attainan adjustable spread of axles with a specific speed variation;

at least one rod-shaped linking member having the number correspondingto the number of the sliding chutes of the disk-type ring wheel, eachrod-shaped linking member consisting of an intermediate cylinder portionand two circular shafts located at both ends of the intermediatecylinder portion;

at least two wedge teeth having the number in relation to the number ofthe circular shafts of the rod-shaped linking member, two wedge teethbeing mounted on each rod-shaped linking member; wherein each wedgetooth consists of first and second wedges of hinge type withcircular-arc-shaped top surfaces and is muff-coupled with one circularshaft of the head portion of the rod-shaped linking member; when thewedge teeth are mounted on the circular shafts of the rod-shaped linkingmember, each rod-shaped linking member is rotatably mounted in theannular recess of the drive wheel via a bearing, the intermediatecylinder portion of the rod-shaped linking member is located in thesliding chute of the disk-type ring wheel and in a movable connectionagainst the sliding chute, and the first and second wedges are expandedby a resilient member, such that the circular-arc-shaped top surfacesand inner walls of the annular recess of the drive wheel create areverse frictional contact when the drive wheel rotates.

The above continuously variable transmission further comprises a I-beamtoothed wheel of I-beam configuration, which is mounted at another sideof the lower portion of the bearer plate of the support via an inputshaft and is adjacent to the toothed wheel on the output shaft, thedrive wheel has two flat wheels which are external-tooth type flatwheels having external toothed portions respectively on theircircumferential surfaces, and two toothed portions of the I-beam toothedwheel are respectively in gear-engagement with the external toothedportions of the external-tooth type flat wheels.

In summary, the continuously variable transmission of the presentinvention adopts a drive wheel, an endless sleeve, a ring wheel, atleast one linking member, and wedge teeth or the like in specific formsof configuration. The drive wheel is provide with an annular recess, inwhich a plurality of reversal wedge teeth run, and the wedge teeth areconnected with a head portion of the linking member with its linkingportion connected with the ring wheel, and the spread of axles betweenthe drive wheel and the ring wheel is adjusted via the swinging of theendless sleeve. By means of the power of the drive wheel and with theaid of the locking and releasing operations of the wedge teeth, thelinking members are urged to drive the ring wheel to change the inputand output transmission ratio. The transmission ratio could generallyreach up to 1:1-1:5 or above. The change of the transmission ratio canbe performed during the travelling of the vehicle to provide acontinuously variable speed variation, with the result of a smooth rideand a reduction in fuel. The continuously variable transmission ispreferably adapted for use in a bicycle, wherein the spread of axlesbetween the ring wheel and the drive wheel is adjusted by regulating awire, such that the magnitude of speed variation is not restricted, thevariation range of the transmission ratio is large, and the power couldbe synchronously input during the speed variation. Thus, thetransmission of the invention has the advantages of being simple instructure, easy in operation, low in noise and abrasion, small in energyloss and great in variation effect.

While the present invention will be described with reference to specificembodiments provided hereinbelow as illustrative and non-limitativeexamples of the present invention, it should be understood by thoseskilled in the art that various modifications may be made theretowithout departing from the spirit and scope of the present invention. Itshould be also noted that like parts in the following figures will bedenoted by like reference numbers for the purpose of betterunderstanding of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial sectional view of a first embodiment of acontinuously variable transmission of the present invention;

FIG. 2 is a side sectional view of FIG. 1;

FIG. 3 is an enlarged view of a portion A of FIG. 1;

FIG. 4 is an exploded view of a linking member and a wedge tooth asshown in FIG. 3;

FIGS. 5 a and 5 b are stereoscopic views of two wedges of the wedgeteeth;

FIG. 6 is a planar design diagram of a circular-arc-shaped wedge surfaceover top surfaces of the wedges shown in FIGS. 5 a and 5 b;

FIG. 7 is a partial sectional view of a second embodiment of thecontinuously variable transmission of the present invention;

FIG. 8 is a structural schematic view of the continuously variabletransmission of FIG. 7 mounted on a bicycle;

FIGS. 9 a-9 c are schematic views showing relations of length of traveland driving angles of the drive wheel and the ring wheel when the spreadof axles thereof is altered to enable the drive wheel to drive the ringwheel driven;

FIG. 10 is a partial sectional view of a third embodiment of thecontinuously variable transmission of the present invention showing thatthe endless sleeve is removed therefrom; and

FIG. 11 is a side sectional view of FIG. 10, showing the meshingengagement of the drive wheel and the I-beam toothed wheel.

DETAILED DESCRIPTION

Referring to FIGS. 1-6, a first embodiment of a continuously variabletransmission of the present invention for motor vehicles or mechanicalequipments is illustrated, comprising a support 1, a drive wheel 2, atoothed wheel 3, an endless sleeve 4, a ring wheel 5, a plurality oflinking members 6, a plurality of wedge teeth 7, an input shaft 8, anoutput shaft 9 and a spring bow 10. The support 1 consists of two bearerplates 11 and a base plate 12, and the bearer plates 11 are verticallymounted at the base plate 12 in a parallel relation and have a pair ofaxle holes arranged at its upper and lower portions, respectively.

The drive wheel 2 is a primary wheel in round shape for power reception,in which an annular recess 22 is arranged near its periphery or outercircumferential surface. The drive wheel 2 is rotatably mounted at theaxle hole of the upper portion of the bearer plate 11 by the input shaft8. In a preferred embodiment, the drive wheel 2 consists of tworelatively oblate flat wheels 21, 21′ of the same size and shape whichare mounted respectively at the input shaft 8 in relatively spaced apartrelation, and a pair of opposite plane symmetric annular recesses 22,22′ are arranged at an inner surface near the periphery or the outercircumferential surface of the drive wheel 2. As the drive wheel 2 isfastened to the input shaft 8, the flat wheels 21, 21′ are always insynchronous rotation.

The toothed wheel 3 is a driven wheel which is an external gear. Thetoothed wheel 3 is rotatably and firmly mounted at the axle hole of thelower portion of the bearer plate 11 by the output shaft 9.

The endless sleeve 4 is a driving element for the purpose of swingingand has an annular groove 41 arranged on its inner circumferentialsurface, and a projecting lug 42 and a mounting cannula 43 respectivelyprotruding outwardly and located at corresponding upper and lowerportions on its outer circumferential surface. The mounting cannulacould be devised to be connected with the annular groove 41, and ismuff-coupled with the output shaft 9 to enable the endless sleeve 4 torotate about the output shaft in a swinging manner to change indirectlythe eccentric spread of axles between the drive wheel and the ring wheelwhile the projecting lug 42 is pushed or pulled back and forth by anexternal force, which will be detailed hereinbelow.

The mounting cannula 43 of the endless sleeve can include two shortcannulas in spaced apart relation and coaxially arranged at oppositesides of the outer wall of the annular groove 41, and correspondingly,the output shaft 9 is provided with a pair of radially spaced flanges91, 91′ arranged against the inner wall of the bearer plate 11. In thisway, the pair of flanges 91, 91′ are rotatably connected with the innerwall of the mounting cannula 43 or the inner walls of the two shortcanulas, such that the rotation of the output shaft 9 allows for urgingthe projecting lug 42 to enable the endless sleeve 4 to swing smoothlyto a given angle. In addition, the spaced arrangement of the mountingcannula 43 provides a space for rotation of the toothed wheel 3.

The ring wheel 5 is an annular external gear, which has, on itsperipheral surface or outer circumferential surface, a gear face ortoothed portion 51 having a relatively large diameter convexintermediate section, and a supporting step 52 having two relativelysmall diameter laterals and recessed with respect to the gear face, i.e.the diameter of the laterals is smaller than the root circle diameter ofthe toothed portion. The ring wheel 5 also has five perforated mountingbulges 53 evenly distributed or arranged on five equipartition portionsof its inner peripheral surface or inner circumferential surface. Thering wheel 5 is mounted in the endless sleeve 4 acting as a swingingelement, and has its toothed portion 51 inserted into the annular grooveof the endless sleeve and meshed with toothed portion of the toothedwheel 3 at the lower portion of the support 1 while being opposite tothe gaps between the walls of the groove. The supporting step 52 of thering wheel 5 is in rolling contact with the top surfaces of both lateralwalls of the annular groove 41. In the present invention, the ring wheel5 is concentrically arranged with the drive wheel 2, and can move withrespect to the drive wheel 2 when the endless sleeve 4 rotates, suchthat their axle centers offset from each other to form an eccentricspread of axles that is adjustable within a specific range. As statedabove, the supporting step 52 of the ring wheel 5 and the top surfacesof both lateral walls of the annular groove 41 of the endless sleeve 4are in the rolling contact by use of a pair of swinging roller bearings60 mounted between the step and the top surface.

The linking member 6 and the bulges of the ring wheel 5 are provided inequal numbers, which amounts to five. Each linking member comprises ahead portion 61 and a linking portion 62. The head portion 61 has anintermediate cylindrical portion 63 and circular shafts 65 located atboth ends of the head portion. The linking portion 62 extends radiallyfrom the intermediate cylindrical portion 63 of the head portion 61 andhas an aperture at its free end. The linking portion 62 of the linkingmember is of a circular-arc configuration and bends in the samedirection as the annular recesses 22, 22′.

Referring again to FIGS. 5 and 6, the number of wedge teeth 7 is ten,which is 2 times of the number of the bulges of the ring wheel. That is,on each linking member two wedge teeth are mounted, and each wedge tooth7 consists of first and second wedges 71, 72 of hinge type withcircular-arc-shaped top surfaces. As the wedges 71, 72 are joined likehinges of a door or window, they are muff-coupled together with thecircular shaft 65 of the head portion 61 of the linking member acting asa hinge axis. After the mounting of the wedge teeth 7 on all thecircular shafts 65 of the linking member, the linking members arerotatably mounted one by one in the annular recesses 22, 22′ by means ofa bearing 64. The free end of the linking portion 62 of each linkingmember is articulated with the bulges 53 of the respective ring wheel bymeans of a pintle. The first and second wedges 71, 72 of each wedgetooth is expanded by a resilient member 10, and the distance betweentheir rotation center and the circular-arc-shaped top surfaces isslightly larger than the relative spacing of the inner walls of theannular recesses of the drive wheel, such that the circular-arc-shapedtop surfaces and the inner walls of the annular recesses create areverse frictional contact when the drive wheel rotates. In the presentembodiment, the first and second wedges 71, 72 respectively have a hingegaine and wedge teats 73, 74 axially arranged at outer circumferentialsurfaces of the gaine. The hinge gaine 75 of the first wedge is locatedat the middle of the wedge teat, and the second wedge has two hingegaines 76, 77 located at both sides of the wedge teat. The hinge gaine75 at the middle could be matchably inserted into the hinge gaines 76,77 at both sides, such that they are aligned with a common axis, whiletheir wedge teats 73, 74 are opposite to each other up and down.

The lateral surfaces 78, 78′ of the wedge teat are planar, and the topsurfaces are circular-arc-shaped wedge surfaces 79, 79′ formed by twosmoothly transited circular arcs with different radii A, B. The arcshave a radius which is relatively large and relatively small at theregion near and far away from the lateral surfaces, respectively.Rabbets 90, 90′ are further provided on the lateral surfaces 78, 78′,and the resilient member is a spring bow 10 with its two ends insertedinto the rabbets 90, 90′ such that the first and second wedges 71, 72are elastically pushed to the circular-arc-shaped wedge surfaces and incontact with the inner walls of the annular recesses 22, 22′ of thedrive wheel 2.

If desired, the present invention further comprises a jogger (not shown)having its one end connected with an opening of the projecting lug 42 ofthe endless sleeve and its another end connected with a control assemblyoutside the transmission (not shown).

Referring to FIGS. 7 and 8 in conjunction with FIGS. 2-6, a secondembodiment of the continuously variable transmission of the presentinvention adapted for a bicycle is shown. The continuously variabletransmission comprises a drive wheel 2, a chain wheel 30, an endlesssleeve 40, a ring wheel 50, a plurality of linking members 6, aplurality of wedge teeth 7, an input shaft 8, an output shaft 9, aspring bow 10 and a chain 80. Obviously, This embodiment is similar instructure, number and connection of the components other than the chainwheel 30, the endless sleeve 40, the ring wheel 50 and the chain 80 tothat disclosed in the first embodiment, which will be omitted herein.Moreover, the support 1 of the first embodiment is now replaced by abicycle frame in this embodiment. It is known that the bicycle frame hasa lower portion provided usually with an axle seat or axle holes for themounting of an intermediate axle, a front axle and a rear axle, whichare not the essence of the invention and will be excluded from theinvention. What the invention is concerned is how to mount thecontinuously variable transmission of the invention onto the axle seatsof the intermediate and rear axles. In this way, the first differentcomponent employed in the second embodiment, the chain wheel 30, is adriven wheel having a center hole as an axle hole for coupling with theoutput shaft 9.

The endless sleeve 40 is a driving element for the purpose of swingingwhich is functionally similar to the endless sleeve 4 of the firstembodiment but differs in structure. The endless sleeve 4 consists of anendless sleeve portion 401 and a handle portion 402 extending outwardlyfrom and integrally with one end of the endless sleeve portion 401. Theendless sleeve portion 401 has an annular groove arranged on its innercircumferential surface (having the same structure as the endless sleeve4 of the first embodiment but not shown in FIG. 7), and a projecting lug404 protruding outwardly from an upper portion of its outercircumferential surface. The handle portion 402 has a fore part on whicha mounting hole 405 capable of rotatably connection with the outputshaft is provided. The endless sleeve 40 is mounted on the output shaft9 through the mounting hole 405, enabling the endless sleeve 40 torotate in a swinging manner about the output shaft 9 when the projectinglug 404 is pushed or pulled back and forth by an external force.

The ring wheel 50 is a hollow annular chain wheel on the bicycle, whichis similar to the ring wheel 5 of the first embodiment but differs inteeth. For example, the ring wheel 5 comprises, on its outercircumferential surface, a toothed portion with a relatively largediameter convex intermediate section and a relatively recessedsupporting step 512 having its both laterals with a diameter smallerthan the root circle diameter of the toothed portion. The ring wheel 5further comprises five perforated bulges evenly distributed on its innercircumferential surface.

The ring wheel is mounted concentrically in the endless sleeve with itstoothed portion inserted into the annular groove of the endless sleeveportion 401 of the endless sleeve. While the supporting step of the ringwheel is in rolling contact with the top surfaces of both lateral wallsof the annular groove, and the ring wheel is concentrically arrangedwith the drive wheel and movable with respect to the drive wheel suchthat their axle centers establish an eccentric spread of axles that isadjustable within a specific range. When the endless sleeve 40 rotatesabout the output shaft 9 in a swinging manner, the ring wheel would bedriven to rotate together whereby changing the eccentric spread of axlesbetween the drive wheel 2 and the ring wheel.

The chain 80 is a bicycle chain mounted on and surrounding the chainteeth of the ring wheel 50 and the chain wheel 30 to drive the rotationof the output shaft 9.

The continuously variable transmission of the first embodiment of thepresent invention operates on the basis of the principles as follows. Inthe operation, the drive wheel 2 mounted at the input shaft 8 is drivenby an external rotary force to rotate in a clockwise direction (asdenoted by the arrow in FIG. 1). If the eccentric spread of axlesbetween the drive wheel 2 and the ring wheel 5 at the startup is 0 (asshown in FIG. 9 c), the wedge teeth 7 are evenly spaced apart on thecircumference where the included angle between the ring wheel and thedrive wheel is 72°, in the annular recesses 22, 22′ near the peripheryof the drive wheel, the two wedges 71, 72 of each wedge tooth expandedby the same spring bow 10 are subject to a resilient force such that thecircular-arc-shaped wedge surfaces 79, 79′ of the top surface of thewedges lean against the opposite wall surfaces of the annular recesses22, 22′. The circular-arc-shaped wedge surfaces and the wall surfaces ofthe annular recesses constitute a reverse frictional contact due to theclockwise rotation of the drive wheel. Therefore, the distance betweenthe circular-arc-shaped wedge surfaces 79, 79′ for all wedge teeth 7 areincreased from small to large, allowing for forcing the wedges 71, 72 tocome intimately contact with the annular recesses until they are lockedup, and then driven by the drive wheel 2 to travel the same length asthe ring wheel 5 urged by the linking portion 62, at this point, theratio of rotation speed of the ring wheel to the rotation speed of thedrive wheel 2 is 1:1.

Thereafter, urging the projecting lug 42 enables the endless sleeve 4 torotate about the output shaft 9 to a specific angle (as shown in FIG.9). Under the action of the endless sleeve 4, the axle center of thering wheel 5 moves away from the axle center of the drive wheel 2, andthe eccentric spread of axles of the drive wheel 2 and the ring wheel 5is changed from 0 to n.

During the rotation of the drive wheel, the wedge teeth 7 in the annularrecess are no longer evenly distributed on the circumference, and thecircumferential distance between the two wedge teeth which are theclosest to the ring wheel 5 is decreased, where the included anglebetween the ring wheel and the drive wheel is 48°. At this point, thesetwo wedge teeth are the closest to the axle center of the ring wheel andreach momentarily a mutual lockup state. Because they are in the samerotation, the rotation speed near the axle center is slower than therotation speed at the position which is away from the axle center, suchthat the wedge teeth, which are the closest to the axle center of thering wheel, would be automatically selected to be locked up when thedrive wheel rotates, and the ring wheel 5 is driven to rotate by urgingthe linking portion 62. It should be noted that these two wedge teethare momentarily locked up at the same time, because they are in analternate state. After slightly moving forward, the wedge teeth in frontwould gradually move away from the axle center and the locking isreleased. The linking portion of the linking member urges the ring wheel5 to move by the wedge teeth in the rear which is locked in the annularrecess; while other wedge teeth are driven by the ring wheel 5 in motionand the linking portion 62 to travel along the annular recess, and theysequentially move away from the axle center of the ring wheel, and thengradually move toward the axle center of the ring wheel again, such thatthe wedge teeth are alternately locked up, and at this point, the ratioof the rotation speed of the drive wheel 2 to the rotation speed of thering wheel 5 is 1:1.5.

By continuously urging the projecting lug 42, the endless sleeve 4 willrotate about the output shaft 9 to a much larger angle (as shown in FIG.9, the included angle between the ring wheel and the drive wheel is24°), following the above principle, the movement of the endless sleeve4 allows the ring wheel 5 to correspondingly move a distance with itsaxle center being deviated more from the axle center of the drive wheel2, thereby the eccentric spread of axles of the drive wheel 2 and thering wheel 5 reaches s. At this point, the ratio of the rotation speedof the drive wheel 2 to the rotation speed of the ring wheel 5 is 1:3.

The drive wheel 2 and the ring wheel 5 are designed to be in aneccentric state, and the drive wheel is forced to rotate by applyingpower thereto, while the ring wheel receives the power from the drivewheel under different spread of axles. When the drive wheel rotates inthe clockwise direction, the annular recess of the drive wheel and thewedge teeth would correspondingly generate a reverse friction, such thatthe wedge teeth in closest proximity to the axle center of the ringwheel move slower than the wedge teeth far away from the axle center ofthe ring wheel, and would be locked up and move synchronously with thedrive wheel. While other wedge teeth are driven by the ring wheel viathe linking member to move sequentially away from and then graduallymove toward the axle center of the ring wheel. The wedge teeth arelocked up and released alternately to realize a continuously variablespeed transmission.

The ingenious integration and association of the drive wheel, the wedgeteeth, the linking members and the ring wheel allow for the change ofthe spread of axles between the drive wheel and the ring wheel with theaid of the swinging of the endless sleeve during the motion of the drivewheel (the design that the swinging of the ring wheel enables the drivewheel to swing is desirable in the invention). In the invention, themoment of force and the rotation speed can be arbitrarily changed andcontinuously variable. When the drive wheel and the ring wheel areconcentrically running, they are in the same revolution in which thelarger the spread of axles between the drive wheel and the ring wheelis, the larger the transmission ratio and the revolution difference are.

The drive wheel and the ring wheel are supposed to be in the state asshown in FIG. 1 or 2, their transmission ratio is 1:3.5, if the spreadof axles between the drive wheel and the ring wheel is maximized. FIGS.9 a-9 c illustrate the change of the spread of axles between the drivewheel and the ring wheel. In the case that the ring wheel is driven bythe drive wheel to travel by 24°, 48°, and 72°, the speed ratio thereofis 1:3, 1:1.5 and 1:1, respectively with respect to the same travelingof 72°.

The continuously variable transmission adapted for the bicycle describedin the second embodiment is similar in operation and principle to thefirst embodiment, even there still exists slight differencestherebetween in structure. For example, the linking member and theannular recess of FIG. 7 are in an 180° reverse connection, such thatthe linking member can drive the ring wheel when a force is applied tothe linking member. This design has the advantage that the linkingmember can be made to be more lightweight and more suitable for thebicycle. The only difference is that in this embodiment, the ring wheelis driven indirectly by the chain wheel through the chain, which isunlike the direct transmission between the ring wheel and toothed wheeldescribed in the first embodiment.

Referring to FIGS. 10 and 11 in conjunction with FIGS. 1-6, a thirdembodiment of the continuously variable transmission of the presentinvention is shown in FIGS. 10 and 11, which is adapted for use in motorvehicles or mechanical equipments as the transmission described in thefirst embodiment. However, the difference therebetween is that the drivewheel drives a disk-type ring wheel via rod-shaped linking members inthis embodiment, while the drive wheel drives the ring wheel via thelinking members in the first embodiment.

In the third embodiment, the continuously variable transmissioncomprises a support 1′, a drive wheel 2′, a toothed wheel 3, an endlesssleeve 4, a disk-type ring wheel 500, a plurality of rod-shaped linkingmembers 60, a plurality of wedge teeth 7 and a spring bow 10. It shouldbe noted that this embodiment only have the disk-type ring wheel 500 andthe rod-shaped linking members 60 that are different from the aboveembodiments, which will be detailed hereinbelow.

Moderate modifications of the support 1′ and the drive wheel 2′ havebeen made in dimension, mounting and connection manners so as to beadapted for the external requirements. The other parts including theswinging roller bearing mounted between the ring wheel and the endlesssleeve remain the same as in the first embodiment in terms of theirstructure, number and connection manner, which is omitted here and fordetails reference can be made to the description of the firstembodiment.

As stated above, one of the differences between the third embodiment andthe above embodiments is the disk-type ring wheel 500, which is adisk-shaped external gear, and comprises a peripheral surface 501 and adisk surface 502. Like the first embodiment, on the peripheral surface501 there exists a toothed portion 511 having a relatively largediameter convex intermediate section, and a relatively recessedsupporting step 512 having its both laterals with a diameter smallerthan the root circle diameter of the toothed portion. On the disksurface 502 a plurality of isometric sliding chutes 521 are radially andequangularly arranged. The disk-type ring wheel 500 is mounted on theendless sleeve 4 (not shown, reference is made to FIGS. 1 and 2 fordetails), and has its toothed portion 511 inserted into the annulargroove 41 of the endless sleeve 4 and meshed with the toothed portion ofthe toothed wheel 3 at the lower portion of the support 1′. Thesupporting step 512 is in slidable contact with the top surfaces of bothlateral walls of the annular groove 41. Moreover, the disk-type ringwheel 500 is concentrically arranged with the drive wheel 2′ and movablewith respect to the drive wheel 2′ to form an adjustable spread of axleswith a specific transmission ratio. Preferably, the sliding chutes ofthe disk-type ring wheel 500 one of the ends adjacent to the center O ofthe ring wheel, and another ends adjacent to the toothed portion of thering wheel.

Another difference between this embodiment and the first embodiment isthe rod-shaped linking member 60, which has the number corresponding tothe number of the sliding chutes 521 of the disk-type ring wheel. Eachof the rod-shaped linking members consists of an intermediate cylinderportion 601 and two circular shafts 602 located at both ends of theintermediate cylinder portion. Like the first embodiment, two wedgeteeth each consisting of first and second wedges of hinge type withcircular-arc-shaped top surfaces are mounted on the circular shaft ofthe rod-shaped linking member 60, and arranged rotatably in the annularrecess of the drive wheel through the muff-coupling to a bearing outsidethe wedge teeth. The intermediate cylinder portion 601 of the rod-shapedlinking member is located snugly in the sliding chutes 521 of thedisk-type ring wheel and establishes a relatively movable transmissionconnection with the sliding chutes. In the annular recess of the drivewheel 2′, the first and second wedges are expanded by a resilient memberto create a reverse frictional contact between their circular-arc-shapedtop surfaces and the inner walls of the annular recess when the drivewheel 2′ rotates.

On the other hand, in the present embodiment, the support 1′ consists oftwo bearer plates and a base plates, but has to been enlarged indimension such that the power input is not limited to the drive wheel.Further, the drive wheel 2′ is modified to be an external-tooth typewheel, which has an external toothed portion on its circumferentialsurface, and is made to act as a driven wheel. In this way, the two flatwheels constituting the drive wheel are two external-tooth type flatwheels 24, 24′ each having external toothed portions 23, 23′ and firmlyattached to the axle 801 of the drive wheel in a spaced manner. Theannular recesses 25, 25′ are respectively arranged on the inner surfacesnear the periphery of the external-tooth type flat wheels 24, 24′, andthe wedge teeth on the two circular shafts of the rod-shaped linkingmembers 60 are respectively located in the annular recesses 25, 25′ ofthe external-tooth type flat wheels. The continuously variabletransmission of this embodiment further comprises a I-beam toothed wheel100 of I-beam configuration mounted at the lower portion of another sideof the bearer plate of the support 1′ adjacent to the toothed wheel 3 onthe output shaft 9 by means of the input shaft 103, with its two toothedportions 101, 102 being respectively in gear-engagement with theexternal toothed portions 23, 23′ of the external-tooth type flatwheels.

When compared with the operation of the first embodiment, the rod-shapedlinking member 60 and disk-type ring wheel 500 of the continuouslyvariable transmission described in the third embodiment are functionallysame as the linking member and the ring wheel of the first embodiment,though the rod-shaped linking member 60 and the disk-type ring wheel 500have been structurally modified, for example, the linking portion of thelinking member 6 of the first embodiment is absent from the rod-shapedlinking member 60, and the disk-type ring wheel is further provided witha disk surface 502 on which the sliding chutes 521 are arranged toenable the rod-shaped linking members 60 to move up and down therein.That is, the sliding chutes in fact correspond to the linking portion ofthe linking member 6 of the first embodiment. In operation, when thedrive wheel 2′ is driven to rotate by the I-beam toothed wheel 100, therod-shaped linking member 60 can receive the power under differentspread of axles between the drive wheel 2′ and the disk-type ring wheel500 to drive the running of the wedge teeth along the annular recess.This is because, when each pair of wedge teeth are respectively mountedon the circular shafts of the rod-shaped linking member 60 and thenfitted into the annular recess of the drive wheel, the intermediatecylindrical portion of the rod-shaped linking member is located in theradial sliding chute 521 of the disk-type ring wheel as a roller. In thecase that the drive wheel and the disk-type ring wheel 500 areeccentrically in a specific spread of axles, the roller would have theannular recess of the drive wheel to act as a circumference andpositioned at different radial positions along the sliding chute of thedisk-type ring wheel. When the drive wheel rotates, the pair of wedgeteeth in the closest proximity to the axle center of the ring wheel orthe pair of wedge teeth on the circular shafts at both ends of theroller, which are the closest to the axle center, would be locked up torotate synchronously, along with the rotation of the disk-type ringwheel driven by the roller. The other wedge teeth would be driven by thedisk-type ring wheel via the sliding chutes to move along the slidingchutes sequentially away from and then gradually move toward the axlecenter of the disk-type ring wheel. The wedge teeth are locked up andreleased alternately to realize a continuously variable speedtransmission.

1. A continuously variable transmission, comprising: a support thatincludes two bearer plates and a base plate; a drive wheel acting as aprimary wheel in round shape, which has an annular recess arranged nearits periphery and is rotatably mounted at an upper portion of the bearerplate by an input shaft; a toothed wheel acting as a driven wheel, whichis rotatably mounted at a lower portion of the bearer plate by an outputshaft; an endless sleeve having an annular groove arranged on its innercircumferential surface, and a projecting lug or driving element and amounting cannula protruding outwardly and located at corresponding upperand lower portions on its outer circumferential surface, respectively; aring wheel which is an annular external gear having on its outerperipheral surface a toothed portion with a relatively large diameterconvex intermediate section and a relatively recessed supporting stephaving its both laterals with a diameter smaller than a root circlediameter of its toothed portion, and a plurality of perforated mountingbulges being evenly distributed on its inner peripheral surface; whereinthe ring wheel is mounted in the endless sleeve and has its toothedportion inserted into the annular groove of the endless sleeve andmeshed with toothed portion of the toothed wheel at the lower portion ofthe support; the supporting step is in slidable contact with topsurfaces of both lateral walls of the annular groove; and the ring wheelis concentrically arranged with the drive wheel and movable with respectto the drive wheel so as to attain an adjustable spread of axles with aspecific speed variation; at least one linking member having the numbercorresponding to the number of the bulges of the ring wheel, eachlinking member comprising a head portion and a linking portion, whereinthe head portion has an intermediate cylindrical portion and twocircular shafts located at its both ends; and the linking portionextends radially from the intermediate cylindrical portion of the headportion and has an aperture at its free end; at least two wedge teethhaving the number in relation to the number of the circular shafts ofthe linking member, two wedge teeth being mounted on each linkingmember; wherein each wedge tooth consists of first and second wedges ofhinge type with circular-arc-shaped top surfaces and is muff-coupledwith one circular shaft of the head portion of the linking member; whenthe wedge teeth are mounted on the circular shafts, each linking memberis rotatably mounted in the annular recess of the drive wheel via abearing, the linking portion of each linking member has its free endarticulated with the bulges of respective ring wheel via a pintle, andthe first and second wedges are expanded by a resilient member, suchthat the circular-arc-shaped top surfaces and inner walls of the annularrecess of the drive wheel create a reverse frictional contact when thedrive wheel rotates.
 2. The continuously variable transmission of claim1, wherein the drive wheel consists of two flat wheels being mountedrespectively at the input shaft in a relatively spaced manner, theannular recess is relatively arranged at an inner surface near peripheryof the flat wheels, and the wedge teeth on the two circular shafts ofthe linking member are respectively located in the annular recess of thetwo flat wheels.
 3. The continuously variable transmission of claim 1,wherein the first and second wedges respectively have a hinge gaine anda wedge teat axially arranged at an outer circumferential surface of thegain, wherein the hinge gaine of the first wedge is located at themiddle of the wedge teat, and the second wedge has two hinge gainesrespectively located at both sides of the wedge treat; and the hingegaine at the middle could be matchably inserted into the hinge gaines atboth sides, such that they are located on a common axis, while theirwedge teats are opposite to each other up and down.
 4. The continuouslyvariable transmission of claim 1, wherein the wedge teat has a lateralsurface which is a flat surface, and a top surface which is acircular-arc-shaped wedge surface constituted by two smoothly transitedcircular arcs with different radii, wherein the arcs have a radius whichis relatively large at the region near the lateral surface andrelatively small at the region far away from the lateral surface, thelateral surface is further provided correspondingly with a rabbet, andthe resilient member is a spring bow having its two ends inserted intothe rabbet, such that the first and second wedges are elastically pushedto the circular-arc-shaped wedge surfaces so as to come into contactwith a inner wall of the annular recess of the drive wheel.
 5. Thecontinuously variable transmission of claim 1, wherein the output shaftis provided with a pair of radially spaced flanges, the mounting cannulaof the endless sleeve consists of two short cannulas in spaced apartrelation and coaxially arranged at opposite sides of an outer wall ofthe annular groove, and the pair of flanges are respectively rotatablyconnected with an inner wall of the short cannula of the mountingcannula.
 6. The continuously variable transmission of claim 1, whereinthe supporting step of the ring wheel and the top surfaces of bothlateral walls of the annular groove of the endless sleeve are in aslidable contact by use of a pair of swinging roller bearings.
 7. Thecontinuously variable transmission of claim 1, wherein both the numbersof the bulges of the ring wheel and the linking members are 4˜7, and thenumber of the wedge teeth is 8˜14.
 8. The continuously variabletransmission of claim 1, wherein the linking portion of the linkingmember is circular arc in shape.
 9. A continuously variabletransmission, comprising: an input shaft and an output shaft arranged inan axle seat of an external support; a drive wheel acting as a primarywheel in round shape, which has its center hole as an axle hole formounting the input shaft, and an annular recess arranged near itsperiphery; a chain wheel acting as a driven wheel, which has its centerhole as an axle hole for mounting the output shaft; an endless sleeveconsisting of an endless sleeve portion and a handle portion extendingoutwardly from one end of the endless sleeve portion, wherein theendless sleeve portion has an annular groove arranged on its innercircumferential surface, and a projecting lug protruding outwardly froman upper portion of its outer circumferential surface, and a fore partof the handle portion is provided with a mounting hole capable ofrotatably connection with the output shaft when the endless sleeveswings; a ring wheel which is an annular chain wheel having on its outerperipheral surface a toothed portion with a relatively large diameterconvex intermediate section and a relatively recessed supporting stephaving its both laterals with a diameter smaller than a root circlediameter of its toothed portion, and a plurality of perforated bulgesbeing evenly distributed on its inner peripheral surface; wherein thering wheel is mounted in the endless sleeve portion of the endlesssleeve and has its toothed portion inserted into the annular groove ofthe endless sleeve portion of the endless sleeve; while the supportingstep is in rolling contact with top surfaces of both lateral walls ofthe annular groove; and the ring wheel is concentrically arranged withthe drive wheel and movable with respect to the drive wheel such thatits axle center and axle center of the drive wheel establish aneccentric spread of axles that is adjustable within a specific range; atleast one linking member having the number corresponding to the numberof the bulges of the ring wheel, each linking member comprising a headportion and a linking portion, wherein the head portion has anintermediate cylindrical portion and two circular shafts located at itsboth ends; and the linking portion extends radially from theintermediate cylindrical portion of the head portion and has an apertureat its free end; at least two wedge teeth having the number in relationto the number of the circular shafts of the linking member, two wedgeteeth being mounted on each linking member; wherein each wedge toothconsists of first and second wedges of hinge type withcircular-arc-shaped top surfaces and is muff-coupled with one circularshaft of the head portion of the linking member; when the wedge teethare mounted on the circular shafts, each linking member is rotatablymounted in the annular recess of the drive wheel via a bearing, and thelinking portion of each linking member has its free end articulated withthe bulges of respective ring wheel via a pintle, and the first andsecond wedges are expanded by a resilient member, such that thecircular-arc-shaped top surfaces and inner walls of the annular recessof the drive wheel create a reverse frictional contact when the drivewheel rotates; a chain mounted on chain teeth of the ring wheel and thechain wheel in an enclosing manner for driving rotation of the outputshaft.
 10. The continuously variable transmission of claim 9, whereinthe drive wheel consists of two flat wheels being mounted respectivelyat the input shaft in a relatively spaced manner, the annular recess isrelatively arranged at an inner surface near periphery of the flatwheels, and the wedge teeth on the two circular shafts of the linkingmember are respectively located in the annular recess of the two flatwheels.
 11. The continuously variable transmission of claim 9, whereinthe first and second wedges respectively have a hinge gaine and a wedgeteat axially arranged at an outer circumferential surface of the gaine,the hinge gain of the first wedge is located at the middle of the wedgeteat, and the second wedge has two hinge gaines located at both sides ofthe wedge treat, respectively; and the hinge gain at the middle ismatchably inserted into the hinge gaines at both sides, such that theyare located on a common axis, while their wedge teats are opposite toeach other up and down.
 12. The continuously variable transmission ofclaim 9, wherein the wedge teat of each wedge has a lateral surfacewhich is a flat surface, and a top surface which is acircular-arc-shaped wedge surface constituted by two smoothly transitedcircular arcs with different radii, wherein the arcs have a radius whichis relatively large at the region near the lateral surface andrelatively small at the region far away from the lateral surface, thelateral surface is further provided correspondingly with a rabbet, andthe resilient member is a spring bow having its two ends inserted intothe rabbet, such that the first and second wedges are elastically pushedto the circular-arc-shaped wedge surface so as to come into contact withan inner wall of the annular recess of the drive wheel.
 13. Thecontinuously variable transmission of claim 9, wherein the output shaftis provided with a radially spaced flange which is rotatably connectedwith a hole wall of the mounting hole.
 14. The continuously variabletransmission of claim 9, further comprising a regulating wire having itsone end connected with the hole of the projecting lug of the endlesssleeve and its another end connected with a control assembly locatedoutside the transmission which is capable of pulling the endless sleeveand elastically retracting, such that a distance between an axle centerof the endless sleeve and the axle center of the drive wheel iscontinuously changed along with the pulling and releasing of theregulating wire.
 15. The continuously variable transmission of claim 9,wherein the supporting step of the ring wheel and the top surfaces ofboth lateral walls of the annular groove of the endless sleeve are inrolling contact by use of a pair of swinging roller bearings.
 16. Thecontinuously variable transmission of claim 9, wherein the linkingportion of the linking member is circular arc in shape.
 17. Acontinuously variable transmission, comprising: a support consisting oftwo bearer plates and a base plate; a drive wheel having an annularrecess arranged near its periphery and being rotatably mounted at anupper portion of the bearer plate by a drive wheel shaft; a toothedwheel acting as a driven wheel, which is rotatably mounted at a lowerportion of the bearer plate by an output shaft; an endless sleeve havingan annular groove arranged on its inner circumferential surface, and aprojecting lug and a mounting cannula protruding outwardly and locatedat corresponding upper and lower portions on its outer circumferentialsurface, respectively; a disk-type ring wheel which is an disk-shapedexternal gear having on its outer peripheral surface a toothed portionwith a relatively large diameter convex intermediate section and arelatively recessed supporting step having its both laterals with adiameter smaller than a root circle diameter of its toothed portion, anda plurality of isometric sliding chutes being radially and equangularlyarranged on its disk surface; wherein the disk-type ring wheel ismounted in the endless sleeve and has its toothed portion inserted intothe annular groove of the endless sleeve and meshed with toothed portionof the toothed wheel at the lower portion of the support; while thesupporting step is in slidable contact with top surfaces of both lateralwalls of the annular groove; and the disk-type ring wheel isconcentrically arranged with the drive wheel and movable with respect tothe drive wheel so as to attain an adjustable spread of axles with aspecific speed variation; at least one rod-shaped linking member havingthe number corresponding to the number of the sliding chutes of thedisk-type ring wheel, each rod-shaped linking member consisting of anintermediate cylinder portion and two circular shafts located at bothends of the intermediate cylinder portion; at least two wedge teethhaving the number in relation to that the number of the circular shaftsof the rod-shaped linking member, two wedge teeth being mounted on eachrod-shaped linking member; wherein each wedge tooth consists of firstand second wedges of hinge type with circular-arc-shaped top surfacesand is muff-coupled with one circular shaft of the head portion of therod-shaped linking member; when the wedge teeth are mounted on thecircular shafts of the rod-shaped linking member, each rod-shapedlinking member is rotatably mounted in the annular recess of the drivewheel via a bearing, and the intermediate cylinder portion of therod-shaped linking member is located in the sliding chute of thedisk-type ring wheel and in a movable connection against the slidingchute, and the first and second wedges are expanded by a resilientmember, such that the circular-arc-shaped top surfaces and inner wallsof the annular recess of the drive wheel create a reverse frictionalcontact when the drive wheel rotates.
 18. The continuously variabletransmission of claim 17, wherein the drive wheel includes two flatwheels being mounted respectively at the drive wheel shaft in arelatively spaced manner, the annular recess is relatively arranged atan inner surface near periphery of the flat wheels, and the wedge teethon the two circular shafts of the rod-shaped linking member arerespectively located in the annular recess of the two flat wheels. 19.The continuously variable transmission of claim 17, wherein the firstand second wedges respectively have a hinge gain and a wedge teat beingaxially arranged at an outer circumferential surface of the gaine,wherein the hinge gain of the first wedge is located at the middle ofthe wedge teat, and the second wedge has two hinge gaines located atboth sides of the wedge treat respectively; and the hinge gaine at themiddle is matchably inserted into the hinge gaines at both sides, suchthat they are located on a common axis, while their wedge teats areopposite to each other up and down.
 20. The continuously variabletransmission of claim 17, wherein the wedge teat has a lateral surfacewhich is a flat surface, and a top surface which is acircular-arc-shaped wedge surface constituted by two smoothly transitedcircular arcs with different radii, wherein the arcs have a radius whichis relatively large at the region near the lateral surface andrelatively small at the region far away from the lateral surface, andthe lateral surface is further provided correspondingly with a rabbet,and the resilient member is a spring bow having its two ends insertedinto the rabbet, such that the first and second wedges are elasticallypushed to the circular-arc-shaped wedge surface so as to come intocontact with a inner wall of the annular recess of the drive wheel. 21.The continuously variable transmission of claim 17, wherein the outputshaft is provided with a pair of radially spaced flanges, the mountingcannula of the endless sleeve consists of two short cannulas in spacedapart relation and coaxially arranged at opposite sides of an outer wallof the annular groove, and the pair of flanges are respectivelyrotatably connected with an inner wall of the short cannula of themounting cannula.
 22. The continuously variable transmission of claim17, wherein the supporting step of the disk-type ring wheel and the topsurfaces of both lateral walls of the annular groove of the endlesssleeve are in a slidable contact by use of a pair of swinging rollerbearings.
 23. The continuously variable transmission of claim 17,wherein both the numbers of the sliding chutes of the disk-type ringwheel and the rod-shaped linking members are 4˜7, and the number of thewedge teeth is 8˜14.
 24. The continuously variable transmission of claim17, wherein the sliding chutes of the disk-type ring wheel have one endsrespectively adjacent to the center of the disk-type ring wheel, andanother ends adjacent to the toothed portion of the ring wheel.
 25. Thecontinuously variable transmission of claims 17, further comprising aI-beam toothed wheel of I-beam configuration, which is mounted atanother side of the lower portion of the bearer plate of the support viaan input shaft and is adjacent to the toothed wheel on the output shaft,the drive wheel has two flat wheels which are external-tooth type flatwheels having external toothed portions respectively on theircircumferential surfaces, and two toothed portions of the I-beam toothedwheel are respectively in gear-engagement with the external toothedportions of the external-tooth type flat wheels.